Our previous work revealed that psychomotor stimulant drugs such as MDMA and methamphetamine induce robust changes in brain temperature. These hyperthermic effects are strongly potentiated by social interaction and warm environment--two conditions often associated with human drug use. In this year, we worked with heroin to establish the role of peripheral and central opioid receptors in mediating hyperthermic effects of this drug. By using multi-site temperature recordings, we clarified the role of metabolic brain activation and skin vascular response in mediating temperature effects of heroin. We also conducted the study to examine how benzodiazepine drugs affect on hyperthermic effects of heroin.